Cable gripping and sheath cutting tool



1966 c. STACKAWICZ CABLE GRIPPING AND SHEATH CUTTING T001:

Filed Aug. 12, 1964 8 9mm kw k 3 mm w a. m

INVENTOR Oar/LSfac/rawkz ATTORNEY United States Patent 3 266 142 CABLE GRIPPING ANl) SHEATH CUTTING TQOL Carl Stackawicz, 73 N. Midland Ave., Kearny, NJ. Fiied Aug. 12, 1964, Ser. No. 389,153 Claims. (Cl. 30-905} The present invention relates to cable sheath gripping and cutting tools and, more especially, to cable sheath gripping and cutting tools which are characterized by having cutter indexing features and are adapted to cut through a convolution of the sheath of a BX cable.

An object of this invention is to provide a manually operable tool having gripping faces for BX cable to be gripped and having a cutter for cutting the sheath of the gripped cable, and which tool automatically produces an increased constraint upon manual operation of the cutter and thus signals to the operator that the cutter has encountered a starting position and to maintain the cutter in the latter position wherein the cable may be received to the gripping faces of the tool without being impeded by thecutter, and from which starting position the sheath thereafter may be easily and effectively cut by further manual operation of the cutter.

Another object of this invention is the provision of a manually operable tool wherein the driving interconnection achieved between the cutter operating arm and the cutter permits the cutter operating arm to be varied in angular position relative to the gripping handles while the cutter remains in the starting position under an increased constraint automatically provided by the tool, and the sheath may thereafter be easily and efficiently cut by manual operation of the cutter from starting position.

Other objects in part will be obvious and in part pointed out more fully hereinafter.

In the accompanying drawing representing a preferred embodiment of the present invention:

FIGURE 1 is a view in side elevation of a gripping and cutting tool in its fully closed position;

FIGURE 2 is a top plan view corresponding to FIG- URE 1 with the retaining thumbscrew for the operating arm removed, and a portion of the operating arm broken away;

FIGURE 3 is a broken away side elevation corresponding to FIGURE 1 with an adaptor positioned in the opening opposite the cutter;

FIGURE 4 is a detail view of the cutter of the tool in the preceding figures;

FIGURE 5 is a detail view of the adaptor corresponding to FIGURE 3; and

FIGURE 6 is a detail view of the cutter assembly in the present embodiment.

Referring now more particularly to the drawing, there is provided a ply gripping and cutting tool 10 which comprises a pair of jaw and handle units respectively including jaws 11 and 12 and handles 15 and 16 connected with the corresponding jaws. A pivot pin 17 extends pivotally securely through adjacent connector portions 13 and 14 of the handle and jaw units, the connector portions being disposed mechanically between the handles and jaws, and the pivot permits the jaws to be opened and closed by operation of the handles.

The jaws 11 and 12 respectively have gripping faces 18 and 24 which extend from side to side of the corresponding jaws and form inner surfaces of the jaws. The gripping faces 18 and 24 are generally of cylindrical curvature modified by ridges 19a and 19b alternating with valleys 20a and 20b and which ridges and valleys are of helical curvature on the respective jaws 11 and 12, extending helically axially transverse to the jaws, for the gripping faces to conform to the external contour of a BX cable sheath. When the jaws are in closed position as illusice trated at FIGURES 1 and 2, the gripping faces 18 and 24 cooperate to form an opening 26 bordered by the ridges 19a and 19b, longitudinally helically aligned in prolongation of each other, and the valleys 20a and 26b, longitudinally helically aligned in prolongation of each other, thus for the valleys to accommodate the convoluted rib of a BX cable sheath and for the ridges to enter the convoluted valley of the sheath for the cable to be gripped by the gripping faces 18 and 24. The jaws 11 and 12 are relieved producing a gap 56 extending from the opening 26 back toward the pivot pin 17 to an inner wall of the l A cutter shaft bore 27 passes through jaw 12 from outside face 23 to the opposed inside'face 22. Bore 27 is situated forward on the jaw 12 from the gripping face 24 and thus is on the far side of opening 26 from the pivot pin 17. A cutter assembly 29 (FIGURE 6) includes a cutter 30 and a shaft 31. The shaft 31 is journaled to jaw 12 in bore 27 and respectively has inner and outer ends 32 and 33. The outer end 33 of the shaft extends outside the outer surface 23 of jaw 12, and includes a first portion 36, shaped for purposes hereinafter to be described, and a second portion 37. The extreme outer end of the shaft has a threaded recess 38 which accommodates a retaining thumbscrew 39. The inner end 32 of the shaft is preferably shaped, such as hexagonally, for driving the cutter 36. There is a peripheral groove 34 in the shaft 31 between the inner end 32 and outer end 33 thereof and the groove receives a generally U-shaped retaining washer 35, which washer bears against the outer surface 23 of the jaw 12 to prevent axial movement of the shaft in the inward direction. The cutter 30 has a central aperture 43 shaped such as hexagonally for the cutter to fit in non-rotatable interlock onto the shaped inner end 32 of the shaft 31. The hexagonal or other comparable shapes of the shaft end 32 and the cutter aperture 43 allow the cutter to be engaged with the shaft 31 in any of a variety of relative angular positions, such as for altering the angular position of the cutter with respect to an operating arm 54 of the tool. A retaining bolt 44 carrying a washer 45 is screwed into an internal bore 46 in the inner end of the shaft to hold the cutter from slipping off the inner end of the shaft. Cutter 30 has a top surface 47 which engages the inner surface 22 of jaw 12 in low pressure contact and this prevents outward axial displacement of shaft 31. The cutter as thus secured to the jaw 12 lies in a cutting plane to which coaxes of bore 27 and shaft 31 are substantially normal.

The cutter 30 is generally in the shape of a disc and has a cutting edge 40 which is continuously along the edges of intermediate projection 41 and a pair of outer projections 42 of the disc having their tips substantially on a chord of the disc. It can be seen from FIGURES 2 and 4 that the outermost sides 42a of the outer projections 42 are radially outwardly from the axis of shaft 31 a greater distance than the distance between the inner sides 42b of the outer projections 42 and the axis of shaft 31. The sides 41a and 41b are even a shorter radial distance from the axis of shaft 31 than are the adjacent sides 42b of the projections 42. This enables the projections to effect a progressively deepening cut in either direction of rotation of the disc.

A bore 28 through the jaw 12, suitably axially parallel to the bore 27, accommodates a detent 49. The detent 49 includes a set screw 50 which is threaded into internal threads 51 in the upper portion of the bore 28, a helical spring 52 which is attached to the bottom of the set' screw 50, and a ball 53 which is attached to the bottom of the spring 52. The detent 49 as assembled to the jaw 12 has a portion of the ball extending beyond the inner surface 22 of the jaw. The diameter of the bore at. its end 0 adjacent the inner surface 22 of jaw 12 advantageously is restricted so that at this end the bore is of less diameter than the diameter of the ball 53 and only a portion of the ball extends below the inner surface 22 of the jaw 12. The fiat surface 47 of the cutter 30 is provided with a semispherical recess 48 which is preferably located on an imaginary diametrical line across the surface of the cutter, through the inner projection 41, and through the axis of the aperture 43. The recess 48 is located on the opposite side of the aperture 43 from the projection 41 and further is radially positioned to be engaged by the detent ball 53.

At this point, it may be desirable to set forth inmore particular the manner in which the detent 49 cooperates with the cutter assembly to index the cutter to a position adjacent to the gripping face 24 in the jaw 12 and wherein the projections 41 and 42 are over the ends of corresponding ones of the ridges 19b and 1911. FIGURE 2 illustrates this index position of the cutter immediately prior to positioning a BX cable in the opening 26. To attain the index position, the cutter 30 is rotated with shaft 31 while the ball 53 bears against flat surface 47 of the cutter. When the cutter has been rotated to a position where the ball 53 enters recess 48, the projections 41 and 42 will be located over corresponding ends of ridges 19b and 19a on the gripping face 24, and the ball 53 thereby indexes the cutter to the proper initial or index position and restrains further rotation of the cutter. The restraining action of the detent is, of course, overcome by sufficient rotative force applied to the shaft 31 when it is desired to initiate further movement of the shaft.

The operating arm 54, having an aperture 55 adjacent to one end thereof, slidably receives the outer end 33 of shaft 31 in this aperture. In configuration, the latter aperture is for example hexagonal or otherwise generally conforms to the cross-sectional shape of the first shaped portion 36 on the outer end of the shaft, so that thus this arm may be drivingly connected with the shaft selectively in any of variety of angular positions relative to the shaft thus to drive the cutter. The second portion 37 on the outer end of the shaft, being circular in cross section is of slightly smaller diameter than the smallest dimension of aperture 55 on the arm 54 so that the arm is journaled to move freely on portion 37. The first shaped portion 36 and second portion 37 on the shaft 31 thereby comprise means for coupling the operating arm 54 to the shaft in first and second positions. In a first position the operating arm surrounds the first shaped portion 36 and rotational movement of the operating arm causes the shaft to be rotated and the rotation is imparted to the cutter 30. When, however, the operating arm is shifted axially of the shaft 31 so that it surrounds the second portion 37, the arm 54 can be rotated independently of the cutter on the shaft 31-to any of a variety of angular positions relative to shaft 31 and then can be shifted axially of this shaft thus selecting any one of a variety of angular positions of engagement with portion 36 from which the cutter 30 may be rotated. The operating arm 54 is bent slightly so as to assure that the arm will clear the handle when the arm is rotated.

Relieved portions 21 and on jaws 11 and 12 respectively cooperate when the jaws are in closed position to form a gap 56 which opens into the opening 26.- An adaptor 57 can be placed in the gap. With reference more particularly to FIGURE 5, the adaptor is generally U-shaped having a bight portion 58 and legs 59 and 60. Leg 59 has an aperture and a thread in the aperture which accommodate a retaining thumbscrew 61. When the adaptor 57 is positioned in gap 56 (see FIGURE 3), the 'bight portion 58 extends into the opening 26 a specified distance according to the corresponding dimension of the 'bight portion. The adaptor is held in place in the gap by inserting the end of thumbscrew 61 into a shallow hole 62 formed in the outer surface of the tool. The thumbscrew 6 1 is not tightened to the extent that there would be any binding action between leg 60 of the adaptor and the adjacent surface of the tool.

With regard to the adaptor, it is interesting to note that while certain groups of different BX cables have different diameters, the width across the convolution in each of the cables is tolerably the same. Also, the pitch of the convolutions of these cables is tolerably the same. Therefore, once a tool provided thusly to accommodate a maximum size cable with which the tool has contemplated usage, the adaptor provides a means to modify the tool in a simple manner to accommodate cable of smaller diameter. It is important for proper functioning that the BX cable be snugly fitted to conform to the ridges and valleys especially in the area adjacent the cutting edge so that the depth of cut will remain substantially constant. The present adaptor serves admirably in this regard in that the cable is forced by the adaptor, on the diametrically opposite side of the opening 26 from the cutter, into firm engagement with the ridges and valleys in the opening adjacent to the cutter. Furthermore, by having a plurality of adaptors available with ditferent effective dimensions, it is only necessary to select the proper adaptor to make the tool useful for any of several cables differing in diameter from each other.

With the foregoing structure in mind, it may be helpful to describe how the tool 10 may be assembled before going into a description of the operation of the tool. The two jaws 11 and 12 with their respective handles 15 and 16 are pivotally interconnected by the pivot pin 17. The detent 49 is positioned in the bore 28 and secured therein by screwing the set screw into the threaded portion 51 of the bore 28. After the washer 35 has been positioned in groove 34, the inner end 32 of the shaft 31 is inserted through the aperture 27 and the extreme inner end of the shaft 31 will project slightly from the inner surface 22 of the jaw 12. The cutter 30 is assembled to the shaft 31 by insertion of the inner end 32 of the shaft through the central aperture 43 of the cutter. The washer 45 and bolt 44 are then assembled to the shaft 31- to hold the cutter in place. The outer end of the shaft is inserted through the aperture in operating arm 54 and the retaining thumbscrew 39 is screwed in place to prevent the operating arm from sliding off the end of the shaft.

When it is desired to use the tool to sever a convolution of the sheath of BX cable, the operating arm 54 is positioned around the first shaped portion 36 of the shaft 31 so as to be in driving engagement with the shaft, and the shaft and cutter 30 are rotated by the operating arm until the ball 53 carried by the jaw 12 enters the recess 48 in the cutter. At this point, and as described above, a projection on the cutter is over the end of a ridge on gripping face and so, while the projection is immediately available to be moved into the opening, there is no obstruction in any of the valleys. Should the projection be misaligned with the ridge, it could obstruct a valley and the misaligned projection would present an obstacle for proper insertion of a section of BX cable. With the projection properly positioned over the ridge, however, the jaws can be opened by operation of the handles and a section of BX cable gripped between the jaws in conformity with the ridges and valleys in the opening 26. Now the operating arm 54 can be moved axially of the shaft 31 to a position surrounding the second portion 37 of the shaft and the operating arm can then be moved independently of the shaft to a desired angular position considering that the handles are held in one hand of the user while the operating arm is manipulated with the other hand. While the operating arm is being so positioned, the detent means serves very well for restraining any movement of the cutter out of its initially aligned position. When the desired position of the operating arm has been reached, the arm is re-positioned around the first shaped portion of the shaft. Now, rotation of the operating arm in either of opposite directions will cause the projection and its associated cutting edge on the sides of the projection to move into a valley then occupied by a convolution of BX cable sheath, and the cutting edge is moved through the sheath. In the event that the cutting edge immediately adjacent the center projection does not cut all the way through the convolution, the rotation of the arm is continued and there will be a progressively deeper cut until the cutting edge on the outer edge of an outer projection enters the valley. It will be understood that no portion of the cutting edge will extend any further into the opening than substantially to the inner surface of the cable sheath. In this manner there is no impairment of insulation on wires extending through the sheath.

If it is desired to sever a convolution of a sheath of BX cable which is smaller in diameter than one which would normally substantially fill the opening, an adaptor 57 is positioned in the gap 56. An adaptor is selected that will have an appropriate dimension to compensate for the particular diameter of the cable when the bight portion 58 extends from the inner wall of the cavity or gap 56 into the opening 26 diametrically opposite from where the cutter enters the opening. When a section of BX cable is placed on a gripping face and the jaws closed, the adaptor will bear against the cable sheath so as to force a portion of the sheath adjacent the cutter firmly against the ridges and into the valleys of the jaws on the side where the cutter enters the opening. Thus, the adaptor serves admirably to suit the tool for use with BX cable which is smaller in diameter than would normally fill the opening and still the desired cut through a convolution of cable sheath is accomplished.

It should now be clear from the above description how the several parts of the tool cooperate with each other to provide worthwhile features. The detent means serves admirably to locate a cutter having a projection in an index position with the projection extending over the end of a jaw ridge. Moreover the detent through the automatic restraint which it provides introduces a definite signal that the index position has been reached.

As many possible embodiments of the invention may be made and as many possible changes may be made in the embodiment herein set forth, it will be distinctly understood that all matter described herein is to be interpreted as illustrative and not as a limitation.

I claim:

1. A ply gripping and cutting tool for BX cable to be gripped on the sheath thereof and cut through a convolution of the sheath, said tool comprising a pair of pivotally connected jaws, handles connected with said jaws for opening and closing the jaws, said jaws having opposed gripping faces thereon forming an opening having its axis disposed laterally of said jaws and said gripping faces having ridges in helical prolongation from jaw to jaw and valleys in helical prolongation from jaw to jaw for a section of BX cable to be disposed between said jaws and be gripped by said gripping faces, an angularly movable cutter carried on said one of said jaws and having a projection with a cutting edge along a side of said projection, detent means having separably engageable portions united with said one of said jaws and said cutter and means relatively biasing said portions to separably engage in response to angular movement of said cutter to an index position wherein said projection of said cutter is over the end of a corresponding one of said ridges between an adjacent pair of said valleys on said one of said jaws, and an operating arm connected with said cutter for angular movement of said arm to be transmitted to said cutter when said arm is angularly moved.

2. A ply gripping tool as set forth in claim 1, wherein said cutter and said operating arm have means united therewith for connecting said arm with said cutter in any of a variety of angular positions while said cutter is in said index position, for angular movement of said operating arm to be transmitted to said cutter when said arm is angularly moved from any of said angular positions selected.

3. A ply gripping and cutting tool as set forth in claim 1, wherein said detent means comprises a detent and a spring biasing said detent united with said one of said jaws, and detent engaging means united with said cutter.

4. A ply gripping and cutting tool as set forth in claim 3, wherein said detent and spring are in a bore in said one of said jaws open to an inner surface of said one of said jaws and said detent projects beyond said inner surface into engagement with a flat surface of said cutter, and said detent engaging means comprises a wall of a recess formed in said flat surface of said cutter.

5. A ply gripping and cutting tool as set forth in claim 1, wherein a shaft journaled on said one of said jaws in a location on the opposite side of said opening from said pivot has inner and outer ends respectively at opposite inner and outer faces of said one of said jaws, said cutter being connected with said inner end of said shaft for angular movement with said shaft; there being first and second shaped portions of said shaft in tandem at said outer end, and said operating arm having an opening, and a wall in said arm opening, for said arm to receive said first and second shaped portions and be moved axially of said shaft from either of said shaped portions to the other, said wall being adapted to freely angularly movably engage said operating arm with said first portion when said arm is shifted onto said first portion, and said arm and said second portion of said shaft having members arranged to engage said arm angularly drivingly with said shaft in any of a variety of angular positions of said arm with respect to said shaft, and said positions being reached by shifting said arm axially of said shaft from corresponding selected angular locations on said first portion onto said second portion.

References Cited by the Examiner UNITED STATES PATENTS 283,378 8/1883 Cook 81-180 1,149,788 8/1915 Shannon 81180 1,603,079 10/ 1926 Hinds 81-180 2,474,940 7/ 1949 Hansen 29283 2,493 ,941 1/ 1950 Belden 3 090.5 2,509,165 5/1950 Pace 29283 2,637,903 5/ 1953 Mallasch 3090.5 2,674,027 4/ 1954 Kosinski 3 090.5 3,107,424 10/ 1963 Stackawicz 3 090.5

WILLIAM FELDMAN, Primary Examiner.

MYRON C. KRUSE, Examiner. 

1. A PLY GRIPPING AND CUTTING TOOL FOR BX CABLE TO BE GRIPPED ON THE SHEATH THEREOF AND CUT THROUGH A CONVOLUTION OF THE SHEATH, SAID TOOL COMPRISING A PAIR OF PIVOTALLY CONNECTED JAWS, HANDLES CONNECTED WITH SAID JAWS FOR OPENING AND CLOSING THE JAWS, SAID JAWS HAVING OPPOSED GRIPPING FACES THEREON FORMING AN OPENING HAVING ITS AXIS DISPOSED LATERALLY OF SAID JAWS AND SAID GRIPPING FACES HAVING RIDGES IN HELICAL PROLONGATION FROM JAW TO JAW AND VALLEYS IN HELICAL PROLONGATION FROM JAW TO JAW FOR A SECTION OF BX CABLE TO BE DISPOSED BETWEEN SAID JAWS AND BE GRIPPED BY SAID GRIPPING FACES, AND ANGULARLY MOVABLE CUTTER CARRIED ON SAID ONE OF SAID JAWS AND HAVING A PROJECTION WITH A CUTTING EDGE ALONG A SIDE OF SAID PROJECTION, DETENT MEANS HAVING SEPARABLY ENGAGEABLE PORTIONS UNITED WITH SAID ONE OF SAID JAWS AND SAID CUTTER AND MEANS RELATIVELY BIASING SAID PORTIONS TO SEPARABLY ENGAGE IN RESPONSE TO ANGULAR MOVEMENT OF SAID CUTTER TO AN INDEX POSITION WHEREIN SAID PROJECTION OF SAID CUTTER IS OVER THE END OF A CORRESPONDING ONE OF SAID RIDGES BETWEEN AN ADJACENT PAIR OF SAID VALLEYS ON SAID ONE OF SAID JAWS AND AN OPERATING ARM CONNECTED WITH SAID CUTTER FOR ANGULAR MOVEMENT OF SAID ARM TO BE TRANSMITTED TO SAID CUTTER WHEN SAID ARM IS ANGULARLY MOVED. 